Methods and apparatus are known for construction of manifolds to direct and control fluids in a complex flow circuit. Typically, flow paths are machined in a metal block in such a configuration as to direct fluid in a logical manner between several control devices. A metal block accomplishes the same paths as could be done with several fittings and interconnecting tubes between the various control devices.
Present manifold designs, for example that disclosed in U.S. Pat. No. 5,094,087, have an inherent problem in that they can be very difficult to assemble into equipment during initial manufacture and, more importantly, difficult and time consuming for repair technicians to diagnose and correct problems in the field. In addition to component malfunctions, debris which may enter the pathways in the manifold or ports of control devices will cause an operational malfunction. The manifold typically cannot be cleared using conventional means and must be partially disassembled or replaced in its entirety. The present manifold design necessitates uncoupling external tubes, devices and wiring harnesses. There is the possibility of wiring connections being made incorrectly during reassembling. Also, special tools are often required and space limitations make reassembly difficult.
The present invention is directed to an improved fluid handling apparatus having a complex flow circuit, a manifold therefor and a method of making the same, which solve these problems through a multi-block manifold design. The manifold comprises a primary manifold block mountable, e.g. permanently mounted, in the fluid handling apparatus, and a secondary manifold block mountable on the primary manifold block. At least one quick-connect connector is provided for quickly, releasably securing the secondary manifold block on the primary manifold block. A plurality of fluid flow paths are provided in the primary and secondary manifold blocks. A plurality of flow control devices are provided on the manifold for controlling fluid flow in the fluid flow paths of the manifold and complex flow circuit of the apparatus. A plurality of manifold ports with connections for external tubes are provided to convey fluid to and from the fluid flow paths in the manifold. According to the invention, the plurality of manifold ports with connections for external tubes are isolated and integral to the primary manifold block and the plurality of flow control devices are integral to the secondary manifold block. This facilitates assembly of the manifold in the apparatus during manufacture, and disassembly and removal of the secondary manifold block from the apparatus during service without disconnecting external tubes and flow control devices from the manifold. In the event of a malfunction within the manifold, the secondary manifold block can be quickly disconnected and removed from the primary manifold block and replaced with a new one and the defective block returned to the factory for diagnosis and repair.
A further feature of the invention is that the plurality of flow control devices of the manifold include electrically operated flow control devices and the manifold includes a wiring harness integral to the secondary manifold block. The wiring harness has wires electrically connected to the electrically operated flow control devices and connected to a common electrical plug. Means are provided on the primary and secondary manifold blocks for aligning the blocks with respect to each other during mounting of the secondary manifold block on the primary manifold block. The means for aligning the blocks and the electrical plug of the wiring harness prevent assembly errors when the two blocks are connected.
The method of the invention for making a manifold for directing and controlling fluid in a complex flow circuit of a fluid handling apparatus, such as a refrigerant recycling machine, comprises providing a multi-block manifold according to the invention and installing the multi-block manifold in the fluid handling apparatus with the primary manifold block permanently mounted in the apparatus and the secondary manifold block quickly, releasably secured on the primary manifold block. The method further includes providing a wiring harness integral to the secondary manifold block with wires of the harness electrically connected to electrically operated flow control devices of the manifold on the secondary manifold block thereby facilitating the assembly of the manifold in the apparatus during manufacture and the disassembly and removal of the secondary manifold block during service without disconnecting external tubes and flow control devices from the manifold.
These and other features and advantages of the invention will become more apparent when taken with the following detailed description of an example embodiment of the invention which is illustrated in the accompanying drawings.